Toner supply device including opening and closing mechanism of toner supply port, and image forming apparatus

ABSTRACT

A toner supply device includes a toner guide, an opening and closing member, and a biasing member. The toner guide guides toner toward a toner supply port. The opening and closing member opens and closes the toner supply port by moving. The biasing member biases the opening and closing member in a closing direction. The opening and closing member includes a base portion, an extension portion, and a toner receiving portion. The base portion faces and closes the toner supply port at the closing position. The extension portion extends downward from an edge of an end portion of the base portion, wherein the edge faces in the closing direction. The toner receiving portion is contracted upon receiving a pressing force in an opening direction, and is expanded upon disappearing of the pressing force and receives toner that has fallen down from the end portion of the base portion.

INCORPORATION BY REFERENCE

This application is based upon and claims the benefit of priority fromthe corresponding Japanese Patent Application No. 2015-231018 filed onNov. 26, 2015, the entire contents of which are incorporated herein byreference.

BACKGROUND

The present disclosure relates to an opening and closing mechanism foropening and closing a toner supply port of a toner guide by using anopening and closing member, and in particular, relates to a toner supplydevice and an image forming apparatus configured to prevent toner leakedfrom a toner supply port from pouring down from an opening and closingmember when the opening and closing member is opened and closed.

A developing device is installed in an image forming apparatus, such asa copier or a printer, that forms an image on a print sheet by theelectrophotography. Developer containing toner is stored in thedeveloping device. The developing device develops an electrostaticlatent image formed on an image carrying member such as a photoconductordrum, by the toner contained in the developer. As the developing isperformed, the toner stored in the developing device is reduced. As aresult, the image forming apparatus includes a toner container storingtoner, and the toner is supplied from the toner container to thedeveloping device. Conventionally, the image forming apparatus includesa toner supply device that supplies the toner from the toner containerto the developing device. The toner supply device includes a toner guidethat guides the toner to a predetermined position. The toner guideincludes a toner supply port and an opening and closing member (shuttermember). The toner is supplied to the developing device via the tonersupply port. The opening and closing member opens and closes the tonersupply port.

According to a conventional image forming apparatus, the developingdevice is attached, in a detachable manner, to a housing of the imageforming apparatus so that the developing device can be replaced. In thistype of image forming apparatus, an opening and closing member is movedfrom a closing position of closing the toner supply port to an openingposition interlockingly with the attachment operation of the developingdevice to the housing. In addition, when the developing device isattached to the housing, a toner replenishing port of the developingdevice is positioned and aligned with the toner supply port. This allowsthe developing device to receive toner supplied from the toner supplyport. In addition, the opening and closing member is biased by a springor the like in a closing direction directed from the opening position tothe closing position, and when the developing device is pulled out fromthe housing, the opening and closing member is moved to the closingposition by the biasing force of the spring.

SUMMARY

A toner supply device according to an aspect of the present disclosureincludes a toner guide, an opening and closing member, and a biasingmember. The toner guide has a toner supply port in a lower end portionthereof and configured to guide toner toward the toner supply port. Theopening and closing member is configured to open and close the tonersupply port by moving between a closing position for closing the tonersupply port and an opening position for opening the toner supply port.The biasing member is configured to bias the opening and closing memberin a closing direction directed from the opening position to the closingposition. The opening and closing member includes a base portion, anextension portion, and a toner receiving portion. The base portion isconfigured to face and close the toner supply port when the opening andclosing member is located at the closing position. The extension portionextends downward from an edge of an end portion of the base portion,wherein the edge faces in the closing direction. The toner receivingportion is provided on a side surface of the extension portion thatfaces in the closing direction and configured to be contracted uponreceiving a pressing force in an opening direction opposite to theclosing direction, and be expanded upon disappearing of the pressingforce and receive toner that has fallen down from the end portion of thebase portion.

An image forming apparatus according to another aspect of the presentdisclosure includes a toner guide, a developing device, an attachmentportion, an opening and closing member, and a biasing member. The tonerguide has a toner supply port in a lower end portion thereof andconfigured to guide toner toward the toner supply port. The developingdevice includes a toner replenishing portion through which the tonersupplied from the toner supply port downward enters an inside of thedeveloping device. The attachment portion is configured to support thedeveloping device in a detachable manner at an attachment position suchthat the developing device can be moved from the attachment position ina first direction of going away horizontally therefrom, wherein thetoner is supplied from the toner supply port and replenished to areplenishing port of the toner replenishing portion when the developingdevice is located at the attachment position and the toner replenishingportion is in contact with the toner supply port. The opening andclosing member is configured to move interlockingly with an attachmentor detachment operation of the developing device with respect to theattachment portion, move to a closing position for closing the tonersupply port when the developing device is moved in the first direction,and move to an opening position for opening the toner supply port bybeing pressed in a second direction by the toner replenishing portionwhen the developing device is moved in the second direction to theattachment position. The biasing member is configured to bias theopening and closing member in a closing direction directed from theopening position to the closing position. The opening and closing memberincludes a base portion, an extension portion, and a toner receivingportion. The base portion is configured to face and close the tonersupply port when the opening and closing member is located at theclosing position. The extension portion extends downward from an edge ofan end portion of the base portion, wherein the edge faces in theclosing direction. The toner receiving portion is provided on a sidesurface of the extension portion that faces in the closing direction, ata position where the toner receiving portion is pressed by the tonerreplenishing portion when the developing device is moved to theattachment position, and configured to be contracted upon receiving apressing force of the toner replenishing portion, and be expanded upondisappearing of the pressing force and receive toner that has fallendown from the end portion of the base portion.

This Summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription with reference where appropriate to the accompanyingdrawings. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used to limit the scope of the claimed subject matter. Furthermore,the claimed subject matter is not limited to implementations that solveany or all disadvantages noted in any part of this disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing a configuration of an image formingapparatus according to an embodiment of the present disclosure.

FIG. 2 is a perspective view showing a toner supply device and adeveloping device according to the embodiment of the present disclosure.

FIG. 3 is a perspective view showing the developing device included inthe image forming apparatus.

FIG. 4 is a cross-sectional view showing a cross-sectional structure ofthe toner supply device and the developing device.

FIG. 5 is a perspective view showing the toner supply device.

FIG. 6 is an enlarged view of a main part VI of FIG. 5, and aperspective diagram showing a toner guide and an opening and closingmechanism of the toner supply device.

FIG. 7 is a perspective view showing the toner guide and the opening andclosing mechanism of the toner supply device.

FIG. 8A to FIG. 8C are schematic diagrams showing an operation of theopening and closing mechanism of the toner supply device during aprocess where the developing device is inserted.

FIG. 9A to FIG. 9C are schematic diagrams showing an operation of theopening and closing mechanism of the toner supply device during aprocess where the developing device is pulled out.

DETAILED DESCRIPTION

The following describes an embodiment of the present disclosure withreference to the attached drawings. It should be noted that thefollowing embodiment is an example of a specific embodiment of thepresent disclosure and should not limit the technical scope of thepresent disclosure. For the sake of explanation in the followingdescription, an up-down direction 6 is defined based on a state where animage forming apparatus 10 according to the embodiment of the presentdisclosure is installed (the state shown in FIG. 1). In addition, afront-rear direction 7 is defined on a supposition that the left of theplane of FIG. 1 is the front side of the image forming apparatus 10. Inaddition, a left-right direction 8 (a direction vertical to the plane ofFIG. 1) is defined on a supposition that the image forming apparatus 10shown in FIG. 1 is viewed from the front side thereof. As a result, thefront side of the plane of FIG. 1 is the right side, and the depth sideof the plane of FIG. 1 is the left side.

[Image Forming Apparatus]

The image forming apparatus 10 has at least a print function. As shownin FIG. 1, the image forming apparatus 10 is, for example, a so-calledtandem-type color printer. The image forming apparatus 10 prints animage on a print sheet by using developer containing toner. It is notedthat the image forming apparatus 10 is not limited to such a printer,but may be any apparatus having the print function such as a facsimileapparatus, a copier, or a multifunction peripheral having a plurality offunctions including the print function. Of course, the image formingapparatus 10 may not form a color image, but form a monochrome image.

As shown in FIG. 1, the image forming apparatus 10 includes, as majorcomponents, four image forming portions 21, an intermediate transferunit 22, a sheet feed device 25, a fixing device 26, a secondarytransfer device 27, an exposure device 24, four toner containers 50(50A-50D), and a toner supply device 60. These components are attachedto a housing 28 (an example of the apparatus main body) that constitutesan external frame (not shown) and an internal frame (not shown) of theimage forming apparatus 10.

The four image forming portions 21 are disposed below the intermediatetransfer unit 22 in the housing 28. The image forming portions 21 arealigned along the front-rear direction 7. The image forming portions 21form toner images respectively on photoconductor drums 11, and transferthe toner images to a transfer belt 23 provided in the intermediatetransfer unit 22 by overlaying the toner images onto the belt insequence. The transfer belt 23 moves in a direction indicated by thearrow 19, and the toner images are transferred in sequence to thetransfer belt 23 while it is moving. In the example shown in FIG. 1, inorder from the downstream side in the movement direction of the transferbelt 23 (the direction of the arrow 19), the image forming portions 21for black, yellow, cyan and magenta are disposed in a row in the housing28.

The image forming portions 21 print an image on a print sheet based onimage data input from outside via a network communication portion (notshown). Each of the image forming portions 21 includes a photoconductordrum 11, a charging device (not shown), a developing device 12, and aprimary transfer device 13. The photoconductor drum 11 carries a tonerimage on its surface. The charging device charges the surface of thephotoconductor drum 11 to a certain potential. The exposure device 24scans the photoconductor drum 11 with a laser beam based on the imagedata. This allows an electrostatic latent image to be formed on thesurface of the photoconductor drum 11. The developing device 12develops, with toner, the electrostatic latent image formed on thecircumferential surface of the photoconductor drum 11. Morespecifically, the developing device 12 causes the toner to adhere to theelectrostatic latent image on the photoconductor drum 11, therebydeveloping the electrostatic latent image with the toner, and forms atoner image as a visual image on the surface of the photoconductor drum11. The primary transfer device 13 transfers the toner image from therotating photoconductor drum 11 to the transfer belt 23.

The developing device 12 performs the developing by using the developerthat contains the toner. As shown in FIG. 2, the developing device 12 iselongated in the left-right direction 8. A container main body 12A ofthe developing device 12 includes a toner replenishing portion 17 (seeFIG. 3). The toner replenishing portion 17 has a replenishing port 18(see FIG. 3). As shown in FIG. 3, the toner replenishing portion 17 isprovided in the container main body 12A at one of its opposite endportions in a longitudinal direction D1. Specifically, the tonerreplenishing portion 17 is provided at the left end portion in the statewhere the developing device 12 is attached to the housing 28.

The developing device 12 is attached to the housing 28 in a detachablemanner so that it can be replaced. A support base 30 (an example of theattachment portion) for supporting the developing device 12 is providedon an inner frame of the housing 28. In the present embodiment, thedeveloping device 12 is supported by the support base 30 in such amanner that it can be inserted to and removed from the housing 28through an opening formed in the right side of the housing 28 (see FIG.1). When the developing device 12 is inserted in an insertion directionD11 (the second direction) directed from the opening of the housing 28to the depth side (the left side in FIG. 3) and reaches a predeterminedattachment position, the developing device 12 is fixed to the attachmentposition by a lock mechanism (not shown). FIG. 2 shows a state where thedeveloping devices 12 are attached to the attachment positions. In thisstate, the toner can be supplied to the inside of the developing device12 via the replenishing port 18 by the toner supply device 60 describedbelow. In addition, when the lock by the lock mechanism is released, andthe developing device 12 is pulled in a direction opposite to theinsertion direction D11, namely, in a removal direction D12 (the firstdirection) of going away horizontally rightward from the attachmentposition, and pulled out from the attachment position, the developingdevice 12 becomes free from the attachment to the housing 28.

As shown in FIG. 1, the intermediate transfer unit 22 is disposed abovethe image forming portions 21. At opposite ends of the intermediatetransfer unit 22 in the front-rear direction 7, a driving pulley 31 anda driven pulley 32 are provided. The transfer belt 23 is supported bythe driving pulley 31 and the driven pulley 32 by being suspendedtherebetween. This allows the transfer belt 23 to move in the directionindicated by the arrow 19. In addition, the transfer belt 23 can movewhile its surface is in contact with the surfaces of the photoconductordrums 11. When the transfer belt 23 passes through between thephotoconductor drums 11 and the primary transfer devices 13, the tonerimages are transferred from the photoconductor drums 11 to the transferbelt 23 such that the toner images are overlaid with each other insequence.

The intermediate transfer unit 22 includes a unit main body 22A (seeFIG. 4) as a housing. The unit main body 22A, as indicated by the dottedline in FIG. 2, is formed in a rectangular parallelepiped shape suchthat it is elongated in the front-rear direction 7 and the left-rightdirection 8, and the size in the up-down direction 6 is shorter than thesizes in the front-rear direction 7 and the left-right direction 8. Theunit main body 22A includes the toner supply device 60 described below.Specifically, the toner supply device 60 is provided in the unit mainbody 22A at the left end portion thereof. The configuration of the tonersupply device 60 is described below.

The secondary transfer device 27 is disposed in a rear portion of thehousing 28. The secondary transfer device 27 transfers, from thetransfer belt 23 to a print sheet, a color toner image formed from thetoner images of the plurality of colors. The print sheet with the colortoner image transferred thereon is conveyed to the fixing device 26. Thefixing device 26 fixes the color toner image transferred to the printsheet, to the print sheet by heat. The fixing device 26 includes aheating roller 26A heated to a high temperature, and a pressure roller26B disposed to face the heating roller 26A. In the fixing device 26,the print sheet is conveyed while being nipped by a predeterminedbiasing force at a nip portion between the heating roller 26A and thepressure roller 26B. This allows the color toner image to be fused andadhere to the print sheet. Subsequently, the print sheet is dischargedonto a sheet discharge tray 29 provided on an upper part of the housing28.

As described above, the image forming apparatus 10 forms a color tonerimage on the surface of the transfer belt 23 by causing the plurality ofimage forming portions 21 to transfer toner images of different colorsonto the running transfer belt 23 such that the toner images areoverlaid with each other. The secondary transfer device 27 thentransfers the color toner image from the transfer belt 23 to a printsheet. In this way, a color image is formed on the print sheet.

As shown in FIG. 1, the four toner containers 50 are disposed above theintermediate transfer unit 22. Inside the housing 28, the four tonercontainers 50 are aligned in a row along the transfer belt 23 in thefront-rear direction 7. The toner containers 50 store toners ofdifferent colors respectively in correspondence with the image formingportions 21. Specifically, the toner containers 50 respectively storetoners of black, yellow, cyan and magenta. The toner stored in each ofthe toner containers 50 is discharged to the toner supply device 60described below from a toner discharge port (not shown) formed in abottom portion of the toner container 50, and is supplied to thedeveloping device 12 of the corresponding color by the toner supplydevice 60.

FIG. 4 is a cross-sectional view of the toner supply device 60 and theintermediate transfer unit 22 taken along a cutting surface that passesthrough a toner conveyance path 36 of the toner supply device 60. FIG. 5is a perspective view showing the toner supply device 60. The tonersupply device 60 is provided in the unit main body 22A of theintermediate transfer unit 22, at the left end portion thereof. Thetoner supply device 60 conveys the toner supplied from the tonercontainers 50, to the developing devices 12 such that the toner issupplied to an inside of each of the developing devices 12 through thereplenishing port 18.

As shown in FIG. 5, the toner supply device 60 roughly includes a tonerconveyance portion 61, four toner guides 62, and an opening and closingmechanism 63.

The toner conveyance portion 61 is formed in a rectangularparallelepiped shape elongated in the front-rear direction 7. The tonerconveyance portion 61 includes a toner conveyance path 36 for conveyingthe toner (see FIG. 4). The toner conveyance path 36 is formed in aninside of the toner conveyance portion 61. The toner conveyance path 36is a passage in which the toner supplied from the toner containers 50 isconveyed to the developing devices 12. In the present embodiment, thetoner conveyance path 36 is formed at each portion that connects from areception port 38 (see FIG. 4) to a communication port 39 provided ineach of the toner guides 62, wherein the reception port 38 and thecommunication port 39 are described below. The toner conveyance path 36extends in the front-rear direction 7 in the toner conveyance portion61. The toner conveyance path 36 is divided into four passages incorrespondence with the four toner containers 50. In each passage, aportion close to an adjacent passage is sealed with a seal member 37 sothat toners of different colors do not mix with each other in the tonerconveyance path 36.

As shown in FIG. 4, a spiral shaft 41 for conveying the toner in thetoner conveyance path 36, is provided in the toner conveyance path 36.The spiral shaft 41 includes spiral blades that are provided around arotation shaft. Upon receiving a driving force and being rotated, thespiral shaft 41 conveys the toner in one direction in the tonerconveyance path 36. In the present embodiment, the spiral shaft 41conveys the toner that has been supplied from the toner containers 50through the reception ports 38 described below, to the communicationports 39 (described below) of the toner guides 62. The toner conveyed tothe communication port 39 falls downward as guided by the toner guide62, and enters the developing device 12 from a lower supply port 66 (anexample of the toner supply port) provided at the lower end of the tonerguide 62, via the replenishing port 18.

As shown in FIG. 5, a plurality of reception ports 38 are providedrespectively in an upper surface portion 61A of the toner conveyanceportion 61. In correspondence with the four toner containers 50, fourreception ports 38 are provided in the upper surface portion 61A. Thereception ports 38 are disposed along the front-rear direction 7 in theupper surface portion 61A. The reception ports 38 penetrate the uppersurface portion 61A downward and are communicated with the tonerconveyance path 36. In addition, in the state where a correspondingtoner container 50 is attached to the housing 28 (hereinafter, the stateis also referred to as a “container attached state”), the reception port38 is communicated with a toner discharge port (not shown) formed in thetoner container 50. That is, in the container attached state, thereception port 38 is located below the toner discharge port. It is notedthat, in order to prevent toner leakage from the toner discharge port,the toner discharge port is brought into close contact with thereception port 38 in the container attached state.

Four communication ports 39 are formed in a lower surface portion 61B ofthe toner conveyance portion 61 (see FIG. 4). The communication ports 39are provided in correspondence with the passages of the toner conveyancepath 36 for different colors. As shown in FIG. 4, the toner guides 62are provided in correspondence with the communication ports 39respectively.

FIG. 6 and FIG. 7 are enlarged perspective views of the toner guide 62.FIG. 6 is a partially enlarged view of a main part VI of FIG. 5. Thetoner guide 62 includes a cylindrical guide portion 62A which extendsdownward from the communication port 39 and whose cross-sectional shapeis a square. The inside of the guide portion 62A is a passage in whichthe toner is conveyed. An upper end of the toner guide 62 is connectedto the communication port 39. In a lower end portion of the toner guide62, a lower supply port 66 (see FIG. 7) is formed. The toner that hasflowed from the communication port 39 into the toner guide 62, movesdownward by its own weight as guided by the guide portion 62A.

A support member 69 is provided in a lower end portion of the guideportion 62A of the toner guide 62. The support member 69 is formedintegrally with the guide portion 62A. The support member 69 is formedin a rectangular parallelepiped shape elongated in the left-rightdirection 8 (horizontal direction). The support member 69 includes thelower supply port 66 that penetrates it in its thickness direction. Thelower supply port 66 is communicated with the inside of the guideportion 62A.

The opening and closing mechanism 63 is attached to the support member69. As shown in FIG. 6 and FIG. 7, the opening and closing mechanism 63is composed of a shutter member 67 (an example of the opening andclosing member), a spring member 68 (an example of the biasing member)such as a coil spring, and a toner receiving portion 80.

The shutter member 67 is attached to the lower end portion of the tonerguide 62. More specifically, the shutter member 67 is attached to alower surface of the support member 69 so as to be able to slidinglymove. That is, the shutter member 67 is slidably supported by thesupport member 69. The shutter member 67 is configured to open and closethe lower supply port 66, and is supported by the support member 69 soas to be able to slidingly move between a closing position (the positionshown in FIG. 6) and an opening position (the position shown in FIG. 7),wherein the shutter member 67 at the closing position closes the lowersupply port 66, and the shutter member 67 at the opening position opensthe lower supply port 66. The shutter member 67 opens and closes thelower supply port 66 by moving between the closing position and theopening position. In the present embodiment, the shutter member 67 isformed from a sheet metal.

Specifically, the shutter member 67 includes a base portion 70configured to face and close the lower supply port 66 when the shuttermember 67 is at the closing position. The base portion 70 is plate-like,and has a flat surface. In addition, the shutter member 67 includes apair of slide guides 71 that respectively extend upward from twoopposite end portions of the base portion 70 in the front-rear direction7. On the extension ends of the slide guides 71, hook rails 72 areformed, where the hook rails 72 are inwardly bent. The shutter member 67is attached to the support member 69 such that the pair of slide guides71 hold opposite ends of the support member 69 in a lateral directionD2. In addition, the hook rails 72 are hooked to upper surfaces of theopposite ends of the support member 69 in the lateral direction D2. Withthis configuration, the shutter member 67 can slidingly move in theleft-right direction 8 with respect to the support member 69.

On the lower surface of the support member 69, an elastic seal member69A is stuck to a peripheral edge of the lower supply port 66. The sealmember 69A is, for example, a sponge member. In the state where theshutter member 67 is disposed at the closing position, the upper surfaceof the base portion 70 is in contact with the lower surface of the sealmember 69A.

As shown in FIG. 6, a spring hook 73 is provided on an upper portion ofa right end portion of the support member 69. In addition, a spring hook74 is provided on an upper portion of a left end portion of the shuttermember 67. The spring member 68 is locked to both the spring hook 73 andthe spring hook 74. Specifically, in the case where the spring member 68is a coil spring, one end thereof is fixed to the spring hook 73, andthe other end is fixed to the spring hook 74. In the present embodiment,the spring member 68 is a so-called tension spring. As a result, in thestate where no external force is applied, the spring member 68 alwaysbiases the shutter member 67 in a closing direction D3 directed from theopening position to the closing position side.

In addition, the shutter member 67 includes an extension portion 77 thatextends downward from an edge of an end portion 67A of the base portion70, wherein the edge faces in the closing direction D3. The extensionportion 77 is plate-like and extends downward from the end portion 67A.The toner receiving portion 80 is attached to the extension portion 77.In the present embodiment, in the shutter member 67, the base portion70, the slide guides 71, the hook rails 72, the spring hook 74, and theextension portion 77 are integrally formed from a sheet metal. On theother hand, the toner receiving portion 80 is provided as a differentmember, independent of the shutter member 67.

In the present embodiment, the extension portion 77 extends downward upto a position where the extension portion 77 is pressed in the insertiondirection D11 by an end portion 17A of the toner replenishing portion 17when the developing device 12 is attached to the attachment position ofthe housing 28. As a result, when the developing device 12 is moved tothe attachment position, the end portion 17A of the toner replenishingportion 17 abuts on the extension portion 77 and presses the shuttermember 67 in the insertion direction D11. Upon receiving the pressingforce, the shutter member 67 moves from the closing position to theopening position in an opening direction D4 against the biasing force ofthe spring member 68. This allows the lower supply port 66 to be opened.On the other hand, when the developing device 12 is pulled out from theattachment position in the removal direction D12, the end portion 17A ofthe toner replenishing portion 17 moves away from the extension portion77. This eliminates the pressing force that has been applied to theshutter member 67 in the insertion direction D11. The shutter member 67then moves in the closing direction D3 directed from the openingposition to the closing position, by the biasing force of the springmember 68. This causes the lower supply port 66 to be closed.

Meanwhile, when the shutter member 67 is opened and closed, toner leakedfrom the lower supply port 66 may accumulate on an upper surface of thebase portion 70. In that case, when the developing device 12 is pulledout from the attachment position of the housing 28 in the removaldirection D12, and the shutter member 67 moves to the closing position,a trace amount of toner that has accumulated on the upper surface of thebase portion 70 may move in the removal direction D12, pour down fromthe end portion 67A of the base portion 70, and smear other members. Inview of this, in the present embodiment, the toner receiving portion 80is provided on the extension portion 77. The toner receiving portion 80is configured to prevent toner from pouring down when the shutter member67 closes the lower supply port 66.

The toner receiving portion 80 plays a role of receiving toner that hasfallen down from the end portion 67A of the base portion 70. The tonerreceiving portion 80 is provided on a side surface 77A of the extensionportion 77 that faces in the closing direction D3 (see FIG. 6). Uponreceiving a pressing force in the opening direction D4 opposite to theclosing direction D3, the toner receiving portion 80 is contracted inthe opening direction D4, and when the pressing force disappears, thetoner receiving portion 80 expands in the closing direction D3. In thepresent embodiment, the toner receiving portion 80 is in a rectangularparallelepiped shape and formed from an elastic member having holesinside, such as a sponge member. The toner receiving portion 80 isadhered to the side surface 77A by an adhesive or the like.

The toner receiving portion 80 is attached to the side surface 77A ofthe extension portion 77 at a position where it is pressed by the endportion 17A of the toner replenishing portion 17 when the developingdevice 12 is inserted in the insertion direction D11 and moved to theattachment position.

In addition, a film member 85 is attached to a side surface of the tonerreceiving portion 80 that faces in the closing direction D3. The filmmember 85 is joined to the side surface of the toner receiving portion80. The film member 85 covers the whole side surface of the tonerreceiving portion 80 and extends upward from an upper surface of thetoner receiving portion 80.

With the above-described configuration of the toner supply device 60,when the developing device 12 is inserted toward the attachmentposition, the end portion 17A of the toner replenishing portion 17 abutson the film member 85 (see FIG. 8A). As the developing device 12 isfurther inserted in the insertion direction D11, the toner receivingportion 80 is contracted by the pressing force of the toner replenishingportion 17 and the biasing force of the spring member 68 (see FIG. 8B).Thereafter, when the developing device 12 is further inserted in theinsertion direction D11, the shutter member 67 moves from the closingposition to the opening position against the biasing force of the springmember 68 while the toner receiving portion 80 is in the contractedstate, and the replenishing port 18 is located below the lower supplyport 66 (see FIG. 8C).

In the present embodiment, in the state where the developing device 12is attached to the attachment position, an upper surface of the tonerreplenishing portion 17 is positioned higher than a lower surface of theseal member 69A. As a result, during the process where the tonerreplenishing portion 17 moves the shutter member 67 to the openingposition while the toner receiving portion 80 is in the contractedstate, the seal member 69A is elastically deformed upward by the uppersurface of the toner replenishing portion 17. Therefore, in the statewhere the developing device 12 is attached to the attachment position,the upper surface of the toner replenishing portion 17 is positionedhigher than a contact surface where the upper surface of the baseportion 70 is in contact with the lower surface of the seal member 69A.

Here, during the process where the toner replenishing portion 17 movesthe shutter member 67 to the opening position, toner that has adhered tothe peripheral edge of the seal member 69A may be pushed in theinsertion direction D11 by the end portion 17A, and fall on an uppersurface of the end portion 67A of the base portion 70. In addition, asdescribed below, during the process where the shutter member 67 moves tothe closing position, toner that has adhered to the seal member 69A maybe pushed in the removal direction D12, and accumulate on the uppersurface of the end portion 67A of the base portion 70.

On the other hand, when the developing device 12 is pulled out from theattachment position in the removal direction D12, the shutter member 67,interlockingly with the movement of the developing device 12 during thepull-out, moves from the opening position toward the closing position(see FIG. 9A). Here, the shutter member 67 moves to the closing positionwhile the toner receiving portion 80 is in the contracted state (seeFIG. 9B). Subsequently, when the developing device 12 is further pulledout in the removal direction D12, the toner replenishing portion 17moves away from the toner receiving portion 80 of the shutter member 67.During the process where the toner replenishing portion 17 moves awayfrom the toner receiving portion 80, the toner receiving portion 80gradually expands from the contracted state, and returns to the originalstate (see FIG. 9C).

When the developing device 12 is pulled out in the removal directionD12, and the shutter member 67 moves from the opening position to theclosing position, toner that has accumulated on the end portion 67A ofthe base portion 70 may move in the removal direction D12 due to themovement of the seal member 69A, and fall down from the end portion 67A.However, the toner receiving portion 80 expands in the removal directionD12 during the process where the toner replenishing portion 17 movesaway from the toner receiving portion 80. As a result, the toner thathas fallen down from the end portion 67A is received by the uppersurface of the toner receiving portion 80. This prevents toner fromfalling down and smearing other members.

In addition, since the toner receiving portion 80 is formed from asponge member, the toner is efficiently caught in the holes provided inthe toner receiving portion 80.

In addition, since the film member 85 is attached to the toner receivingportion 80, the toner received by the upper surface of the tonerreceiving portion 80 is prevented from overflowing and pouring down. Itis noted that in the present embodiment, a configuration including thefilm member 85 is described. However, the film member 85 may not benecessarily provided. As a result, the present disclosure is applicableto a configuration where only the toner receiving portion 80 is attachedto the extension portion 77.

It is to be understood that the embodiments herein are illustrative andnot restrictive, since the scope of the disclosure is defined by theappended claims rather than by the description preceding them, and allchanges that fall within metes and bounds of the claims, or equivalenceof such metes and bounds thereof are therefore intended to be embracedby the claims.

The invention claimed is:
 1. A toner supply device comprising: a tonerguide having a toner supply port in a lower end portion thereof andconfigured to guide toner toward the toner supply port; an opening andclosing member configured to open and close the toner supply port bymoving between a closing position for closing the toner supply port andan opening position for opening the toner supply port; and a biasingmember configured to bias the opening and closing member in a closingdirection directed from the opening position to the closing position,wherein the opening and closing member includes: a base portionconfigured to face and close the toner supply port when the opening andclosing member is located at the closing position; an extension portionextending downward from an edge of an end portion of the base portion,the edge facing in the closing direction; and a toner receiving portionprovided on a side surface of the extension portion that faces in theclosing direction and configured to be contracted upon receiving apressing force in an opening direction opposite to the closingdirection, and be expanded upon disappearing of the pressing force andreceive toner that has fallen down from the end portion of the baseportion.
 2. The toner supply device according to claim 1, wherein theopening and closing member further includes a film member that isprovided on a side surface of the toner receiving portion that faces inthe closing direction, and extends upward from an upper surface of thetoner receiving portion.
 3. The toner supply device according to claim1, wherein the toner guide includes an elastic seal member on aperipheral edge of the toner supply port.
 4. The toner supply deviceaccording to claim 1, wherein the toner receiving portion is an elasticmember having holes inside.
 5. The toner supply device according toclaim 1, wherein the opening and closing member is formed from a sheetmetal.
 6. An image forming apparatus comprising: a toner guide having atoner supply port in a lower end portion thereof and configured to guidetoner toward the toner supply port; a developing device including atoner replenishing portion through which the toner supplied from thetoner supply port downward enters an inside of the developing device; anattachment portion configured to support the developing device in adetachable manner at an attachment position such that the developingdevice can be moved from the attachment position in a first direction ofgoing away horizontally therefrom, the toner being supplied from thetoner supply port and replenished to a replenishing port of the tonerreplenishing portion when the developing device is located at theattachment position and the toner replenishing portion is in contactwith the toner supply port; an opening and closing member configured tomove interlockingly with an attachment or detachment operation of thedeveloping device with respect to the attachment portion, move to aclosing position for closing the toner supply port when the developingdevice is moved in the first direction, and move to an opening positionfor opening the toner supply port by being pressed in a second directionby the toner replenishing portion when the developing device is moved inthe second direction to the attachment position; and a biasing memberconfigured to bias the opening and closing member in a closing directiondirected from the opening position to the closing position, wherein theopening and closing member includes: a base portion configured to faceand close the toner supply port when the opening and closing member islocated at the closing position; an extension portion extending downwardfrom an edge of an end portion of the base portion, the edge facing inthe closing direction; and a toner receiving portion provided on a sidesurface of the extension portion that faces in the closing direction, ata position where the toner receiving portion is pressed by the tonerreplenishing portion when the developing device is moved to theattachment position, and configured to be contracted upon receiving apressing force of the toner replenishing portion, and be expanded upondisappearing of the pressing force and receive toner that has fallendown from the end portion of the base portion.
 7. The image formingapparatus according to claim 6, wherein the opening and closing memberfurther includes a film member that is provided on a side surface of thetoner receiving portion that faces in the closing direction, and extendsupward from an upper surface of the toner receiving portion.
 8. Theimage forming apparatus according to claim 6, wherein the toner guideincludes an elastic seal member on a peripheral edge of the toner supplyport.
 9. The image forming apparatus according to claim 6, wherein thetoner receiving portion is an elastic member having holes inside. 10.The image forming apparatus according to claim 8, wherein in a statewhere the developing device is attached to the attachment position, thetoner replenishing portion is in contact with the toner supply port viathe seal member while elastically deforming the seal member upward, andthe opening and closing member at the closing position closes the tonersupply port while causing an upper surface of the base portion to be incontact with a lower surface of the seal member.
 11. The image formingapparatus according to claim 6, wherein the opening and closing memberis formed from a sheet metal.